TupleDesc reference leak #3

Hello,
Just downloaded and installed. Thanks for all the good work! Here is an issue that came up:
(Running Postgresql 8.4.5 on Ubuntu 2.6.32-25-server)
CREATE TABLE emp
(
"name" character varying(32),
salary int4
);
INSERT INTO emp("name", salary) VALUES ('bill', 1200);
INSERT INTO emp("name", salary) VALUES ('jim', 900);
INSERT INTO emp("name", salary) VALUES ('joe', 1500);
then
CREATE OR REPLACE FUNCTION overpaid_2 (EMP) RETURNS bool AS
'
args[0]["salary"] > 1000
' LANGUAGE 'plruby';

SELECT name, overpaid_2(emp) from emp;
get correct output, but following warnings:
2010-12-04 16:14:38 PST WARNING: TupleDesc reference leak: TupleDesc 0x7f5c97f01030 (49442,-1) still referenced
2010-12-04 16:14:38 PST WARNING: TupleDesc reference leak: TupleDesc 0x7f5c97f01030 (49442,-1) still referenced
2010-12-04 16:14:38 PST WARNING: TupleDesc reference leak: TupleDesc 0x7f5c97f01030 (49442,-1) still referenced
Any ideas here?